Ignoring the increase in unsprung weight, the advantages of in-wheel power sources are obvious.
With each unit sitting in the space inside a wheel, supplying power exactly where and when the driver requires, means that gearboxes, driveshafts and differentials are no longer necessary, eliminating weight while also improving the efficiency of power transfer.
In addition, each in-wheel motor can be controlled entirely independently, providing far greater control, performance and vehicle dynamics than any other drive system.
And if that isn’t enough, traction control, launch control and torque vectoring are all easily implemented through their use.
Unfortunately, the technology has never passed the concept phase. However, today, a company known as Protean has announced that its in-wheel motor design is headed for production.
Protean is showing its in-wheel motor at the 2013 Society of Automotive Engineers World Congress today and promises to start volume production in 2014 at a new plant in Liyang, China.
Each of its motors weigh 68 pounds and produce 75 kilowatts (100 horsepower) and as much as 735 pound-feet of torque. They also offer superior regenerative braking capabilities, enabling up to 85 percent of the available kinetic energy to be recovered during braking.
Importantly, Protean sees its in-wheel motors as an integral part of a hybrid powertrain system where they are paired with a traditional internal combustion engine. They can also be retrofitted to existing vehicles, as long as the wheels measure between 18 and 24 inches in diameter.
As part of a hybrid system, the motors should reduce fuel consumption by as much as 30 percent versus a vehicle without the motors. At the same time, Protean states the motors are also powerful enough to be the only source of traction drive.